The South African government issued a sweeping new ban today on outdoor funerals with any political content in black townships, a measure immediately denounced by opposition leaders who warned that it would increase tensions in the riot-torn communities.

Nobel Peace Prize winner Bishop Desmond Tutu quickly vowed to speak at a funeral scheduled for Thursday and said the government is "playing with fire" in banning the funerals, which have served as a "safety valve" for "a people already battered by vicious and draconian laws."

Another man was killed in clashes with police in the eastern Cape Province area today, and unrest continued in the Cape Town and Durban areas not covered by the state of emergency the government declared 11 days ago.

Meanwhile, a private media council upheld published allegations that security police had conducted a smear campaign against the Rev. Allan Boesak, one of the country's leading activists against the system of strict racial segregation called apartheid.

Funerals for blacks killed by police during episodes of unrest have become a principal means of publicly demonstrating opposition to the government in recent months, drawing as many as 70,000 people. They have been filled with angry rhetoric and the flaunting of outlawed slogans and banners. Many have flared into violence.

Government officials, including Law and Order Minister Louis le Grange, have said the new measures were designed to defuse tensions in the townships by denying activists one of their most important forums for stirring unrest. But opponents warned that the restriction, by closing off one of the few remaining channels of legal protest, would only make things worse.

The new government ban forbids outdoor services for anyone who dies of unnatural causes in any of the 36 districts around Johannesburg and Port Elizabeth covered by the state of emergency.

The measure also includes a ban on any political statements at a service, and forbids the use of public address systems and the distribution or display of flags, placards or pamphlets. It orders that the presiding clergyman "shall not . . . in any manner defend, attack, criticize, propagate or discuss any form of government, any principle or policy of a government of a state, any boycott action, the existence of a state of emergency or any action by a force or a member of a force."

Anyone who violates the ban faces up to 10 years in prison and a $10,000 fine.

In an interview on British television, Tutu said he was "appalled" by the ban on funerals, because the authorities "are now trying to prescribe to the black community when and how to mourn, and I think that is . . . quite intolerable."

He said he did not know what the government's reaction would be if he spoke about the political situation at Thursday's funeral, and added: "If we are going to be able to exercise any kind of control and call people to be restrained, we surely need to refer to the situation in which they find themselves."

At the mass outdoor funerals, he said, people were able to "give expression to their hurt, and there was a kind of healing . . . . It was possible for religious leaders then to be able to exercise some form of control and influence on how things developed from that kind of situation."

The South African Council of Churches, in a statement by General Secretary Beyers Naude, asked the government to reconsider the move, warning that "anger will increase and we fear that a situation may arise where the community, in their frustration, will eventually defy such restrictions, thereby causing more conflict and clashes."

Boesak, a Dutch Reformed minister who is a founder of the United Democratic Front opposition movement, said the restrictions were "sure to cause more confrontation and bloodshed."

In the other matter affecting Boesak, the South Africa Media Council dismissed a complaint brought by the security police against The Johannesburg Star. The newspaper had published articles earlier this year reporting that police had helped distribute pamphlets and tape recordings alleging that the minister, who is of mixed race, was having an affair with a white woman.

The council ruled that "certain members of the security police, whose identities are not clear from the evidence, were implicated" in disseminating the material to The Star and possibly to other newspapers. It ruled that two police colonels had admitted this to two reporters in interviews, although they had told the reporters they would deny the admissions if they were published.

Boesak, who has said he had a "very close" and "unique" relationship with the woman, said the ruling confirmed police had conducted a "dirty tricks" campaign against him.

Police also announced today that they had arrested eight persons in connection with the murder of Maki Skosana, an alleged police informer who was stoned and burned alive July 20 by a mob.

Incidents of unrest continued today in several black townships, police reported.

In the eastern Cape Province town of Cathcart a man was killed by shotgun fire when police dispersed a stone-throwing crowd that had attacked a town councilman's house. The death was the 25th since the emergency was proclaimed by President Pieter W. Botha to quell the unrest that has rocked this country for the past 11 months. The death toll since last September is now about 500 people.

Police announced 44 new arrests today, bringing to 1,259 the total made under the emergency proclamation. Thirteen persons have been released.

* EC Envoys to S. Africa ---To Be Summoned Home --Reuter

HELSINKI, Aug. 1 (Thursday) -- European Community foreign ministers today agreed to summon home their ambassadors in South Africa in the near future to help draw up a new strategy for putting pressure on Pretoria to abandon its apartheid policy.

One foreign minister, who asked not to be named, said the decision fell short of formally recalling the envoys but added: "It is clearly intended as a warning to Pretoria."

A call for tougher measures such as restrictions on investments and travel to South Africa, made by Belgium, was met with caution, particularly by West Germany and Britain.